example.py

"""Minimal usage example for hv-note.

If you have ESC-50 or FSDD locally, edit the paths below.
Otherwise this file synthesizes a small WAV and scores it.
"""
import math
import os
import wave
from array import array

from hv_note import HVNote


OUTDIR = "./hv_note_example"
WAV_PATH = os.path.join(OUTDIR, "example.wav")


def _synth(path: str, sr: int = 16000) -> None:
    os.makedirs(os.path.dirname(path), exist_ok=True)
    sig = []
    for f, dur_ms in [(440, 150), (660, 150), (880, 250)]:
        n = int(sr * dur_ms / 1000)
        for i in range(n):
            t = i / sr
            env = math.sin(math.pi * i / n) ** 0.5
            sig.append(0.5 * env * math.sin(2 * math.pi * f * t))
        sig.extend([0.0] * int(sr * 0.1))
    ints = array(
        "h",
        (max(-32768, min(32767, int(x * 32767))) for x in sig),
    )
    with wave.open(path, "wb") as w:
        w.setnchannels(1)
        w.setsampwidth(2)
        w.setframerate(sr)
        w.writeframes(ints.tobytes())


def main() -> None:
    _synth(WAV_PATH)
    model = HVNote()
    report = model.score_file(WAV_PATH)

    print("=" * 60)
    print("hv-note")
    print("=" * 60)
    print(model.render_file(report))
    print()

    print("=" * 60)
    print("Numeric summary")
    print("=" * 60)
    print(f"  file         : {report.path}")
    print(f"  duration     : {report.duration_s:.3f} s")
    print(f"  sample rate  : {report.sample_rate} Hz")
    print(f"  events       : {len(report.events)}")
    print(f"  unique sym   : {len(report.histogram)}")
    print(f"  entropy      : {report.entropy_bits:.4f} bits")
    print(f"  score        : {report.score}")
    print(f"  fingerprint  : {model.fingerprint(WAV_PATH, k=8)}")
    print()


if __name__ == "__main__":
    main()